Ovipositor

Some ovipositors partially retract when not in use. The basal part that protrudes is known as the scape or oviscape, the word scape deriving from the Latin word scāpus, meaning "stalk" or "shaft".

In insects

Grasshoppers use their ovipositors to force a burrow into the earth to receive the eggs. Cicadas pierce the wood of twigs with their ovipositors to insert the eggs. Sawflies slit the tissues of plants with their ovipositor as do some species of long-horned grasshoppers. In the ichneumon wasp genus Megarhyssa, the females have a slender ovipositor (terebra) several inches long that is used to drill into the wood of tree trunks. These wasps are parasitic in the larval stage on the larvae of horntail wasps, hence the egg must be deposited directly into the host's body as it is feeding. The ovipositors of Megarhyssa are among the longest egg-laying organs (relative to body size) known.

The stingers of the Aculeata (wasps, hornets, bees, and ants) are ovipositors, highly modified and with associated venom glands. They are used to paralyze prey, or as defensive weapons. The penetrating sting plus venom allows the wasp to lay eggs with less risk of injury from the host. In some cases, the injection also introduces virus particles that suppress the host's immune system and prevent it from destroying the eggs. However, in virtually all stinging Hymenoptera, the ovipositor is no longer used for egg-laying. An exception is the family Chrysididae, members of the Hymenoptera, in which species such as Chrysis ignita have reduced stinging apparatus and a functional ovipositor.

Fig wasp ovipositors have specialized serrated teeth to penetrate fruits, but gall wasps have either uniform teeth or no teeth on their ovipositors, meaning the morphology of the organ is related to the life history.

Members of the Dipteran (fly) families Tephritidae and Pyrgotidae have well-developed ovipositors that are partly retracted when not in use, with the part that sticks out being the oviscape. Oestridae, another family within Diptera, often have short hairy ovipositors, the species Cuterebra fontinella has one of the shortest within the family.

Ovipositors exist not only in winged insects, but also in Apterygota, where the ovipositor has an additional function in gathering the spermatophore during mating. Little is known about the egg-laying habits of these insects in the wild.